Radiation shielding of three dimensional multi-chip modules

ABSTRACT

The invention discloses a method for making two sided Multi-Chip Modules (MCMs) that will allow most commercially available integrated circuits to meet the thermal and radiation hazards of the spacecraft environment using integrated package shielding technology. The invention to describes the technology and methodology to manufacture MCMs that are radiation-hardened, structurally and thermally stable using 3-dimensional techniques allowing for high density integrated circuit packaging in a radiation hardened package.

[0001] Provisional Application No.:

[0002] 60/010,726 filed Jan. 29, 1996

[0003] References Cited: U.S. Pat. Nos. 5,578,526, 5,502,289, 5,495,398,5,495,394, 5,436,411, 5426,566, 5,422,435, 5,324,952, 4,833,334

[0004] U.S. patent applications Ser. Nos. 08/221,506, 08/372,289

TECHNICAL FIELD

[0005] The present invention relates in general to an improved methodfor radiation shielding of microelectronic devices. The invention moreparticularly relates to packaging designs and processes formanufacturing improved radiation tolerant 3-dimensional ceramic andmetal packaged microelectronic multi-chip modules (MCMs).

[0006] This is a Continuation Patent Application of U.S. patentapplication Ser. No. 09/109,954, filed Jul. 2, 1998 for RADIATIONSHIELDING OF THREE DIMENSIONAL MULTI-CHIP MODULES, of Czajkowski, et al,

[0007] which is a Divisional Patent Application of U.S. patentapplication Ser. No. 08/788,134, filed Jan. 24, 1997 for RADIATIONSHIELDING OF THREE DIMENSIONAL MULTI-CHIP MODULES, of Czajkowski, et al,now U.S. Pat. No. 5,880,403,

[0008] which is a Continuation in Part of U.S. patent application Ser.No. 08/372,289, filed Jan. 13, 1995 for RADIATION SHIELDING OFINTEGRATED CIRCUITS AND MULTI-CHIP MODULES IN CERAMIC AND METALPACKAGES, of Strobel, et al., now U.S. Pat. No. 5,635,754,

[0009] which is a Continuation in Part of U.S. patent application Ser.No. 08/221,506, filed Apr. 1, 1994 for RADIATION SHIELDING OF PLASTICINTEGRATED CIRCUITS, of Strobel, et al, now abandoned.

[0010] U.S. patent application Ser. No. 08/788,134, filed Jan. 24, 1997for RADIATION SHIELDING OF THREE DIMENSIONAL MULTI-CHIP MODULES, ofCzajkowski, et al, is a Continuation in Part of U.S. patent applicationSer. No. 08/595,266, filed Feb. 1, 1996 now U.S. Pat. No. 5,889,316,

[0011] which is a continuation of U.S. patent application Ser. No.08/372,235, filed Jan. 13, 1995 now U.S. Pat. No. 5,825,042,

[0012] which is a continuation of U.S. patent application Ser. No.08/077,731, filed Jun. 18, 1993 now abandoned.

[0013] All of the above patent applications are hereby incorporatedherein by reference.

BACKGROUND OF THE INVENTION

[0014] Many of today's commercial integrated circuit (IC) devices andmulti-chip modules (MCM) cannot be utilized in deep space and earthorbiting applications because of Total Dose radiation induced damage.Commercial IC devices are developed and manufactured for the computerand mass market applications and are not designed to withstand theeffects of the natural space environment. The type and source ofradiation in space include solar flares, galactic cosmic radiation andthe Van Allen trapped electron and proton belts or man-made radiationinduced events (neutrons and gamma radiation).

[0015] Commercially available metal packaged integrated circuits andmulti-chip modules have not been used in spacecraft applications becauseof both perceived and real reliability problems. Some examples ofcommercial multi-chip modules are U.S. Pat. Nos. 5,578,526, 5,502,289,5,495,398, 5,495,394, 5,436,411, 5,422,435. The major issues needing tobe addressed for commercial integrated circuits in order for them to flyin space are the reliability and survivability of these devices whenexposed to spacecraft environmental hazards such as total dose levels ofelectrons, protons, solar flares, and cosmic radiation. Typical siliconintegrated circuit plastic, ceramic, metal and multi-chip modulepackaged devices will fail to operate when exposed to total doses of 2to 15 Krads(Si). Since communication satellites are expected to functionin orbit for periods of 8 to 15 years, this would rule out almost allcommercially available packaged silicon integrated circuit devices andmulti-chip modules.

[0016] Common methods used to prevent radiation degradation inperformance for integrated circuits are: 1) design special radiationtolerant die, 2) screen each part for radiation tolerance, or 3) shieldthe package or the platform. There are tradeoffs with each of thesemethods. The first example usually is the most radiation tolerant. Herethe die is specially designed to be radiation tolerant. However, thismethod is both time consuming and expensive to produce since the partmust be redesigned to incorporate radiation hardening techniques.Examples of this method include U.S. Pat. Nos. 5,324,952, 5,220,192,5,140,390, 5,024,965, 5006,479, 5,001,528, 4,903,108, 4,825,278,4,675,978, 4,402,002, 4,313,7684, 4,148,049, 4,014,772, and 3,933,530.This method delays the time to market such that these radiation hardeneddevices are usually 2 to 3 generations behind the current commercialtechnological advances in both size and capabilities. There areadditional penalties in limited marketability and demand for theproduct. The result is a higher cost from low volume productions of thedie. The end result, is that this method produces; 1) a more expensiveproduct that is 2) technologically behind current commercially availablemicroelectronics, 3) frequently with slower speed and 4) lesscapability. Additionally because of the limited market for theseproducts, frequently they are not available at all.

[0017] The second method involves testing each part or die lot in thehopes that the die will meet the mission radiation requirements. Thiscould be an expensive process because of the large amount of testingthat would be required and the low probability of success in finding aninherently radiation tolerant die that meets the mission requirements.This problem is compounded for Multi-chip Modules in that all the dierequired in the package need to be radiation tolerant. This is not onlyextremely restrictive on the design and expensive because of the amountof testing but it is highly unlikely that all the required die will befound that will meet the radiation requirements of the mission.

[0018] The third method involves shielding the part. This methodincludes either shielding the entire satellite, subsystem or individualpart. Shielding the satellite or subsystem carries extreme weight andsize penalties that generally make this solution cost prohibitive. Thespacecraft has some inherent shielding the skin and spacecraftcomponents, however this is very difficult to model and generallydoesn't provide adequate shielding for all parts and directions.

[0019] An example of system level shielding is U.S. Pat. No. 4,833,334,which is incorporated by reference as if fully set forth herein,describes the use of a protective box to house sensitive electroniccomponents. This box is partially composed of a high atomic weightmaterial to effectively shield against x-rays. However this approach hasthe serious disadvantage off adding substantial bulk and weight toelectronic circuit assemblies protected in this manner. Moreover, itwould be expensive to provide this type of protection to individualintegrated circuits as manufacturing custom boxes for each circuitconfiguration would be costly. Similarly U.S. Pat. No. 5,324,952,follows a method of shielding components. If shielding is required thebetter method is to shield only the components that require shielding.

[0020] One method of shielding individual components is know as spotshielding. With this method, a small shield is attached to the surfaceof the package. However this method does not provide effective3-dimensional shielding protection. Additionally, the external shield isgenerally thermally mismatched to the package, and increases the sizeand weight of the package. Often a bottom spot shield cannot be used dueto the inability to accommodate a fixed lead length. The spot shieldalso has no mechanical support except the adhesive used to attach it tothe surface of the package.

[0021] An example of spot shielding is disclosed in Japanese patentpublication 62-125651, published Jun. 6, 1987 which is incorporated byreference as if fully set forth herein. This patent describes a spotshielded semiconductor device which utilizes a double layered shieldfilm to a sealing cover on an upper surface of the semiconductor packageand attaching another double layered shield film to a lower surface ofthe package. However, space qualified microelectronic parts must becapable of withstanding the enormous forces exerted during accelerationperiods. The external shields are subject to tearing or prying off fromthe sealing cover. The use of a double layer shield film only slightlyreduces the weight of the package but increases the size of the packageunnecessarily. Also thin films are generally only effective at shieldingElectromagnetic Interference (EMI) radiation and are ineffective atshielding ionizing radiation found in space. Examples of this type ofEMI or EMF shielding devices include U.S. Pat. Nos. 4,823,523, 4,868,716and 4,266,239.

[0022] The significant disadvantage of the spot shielding method includean increase in weight and thickness of the device, an increase inexposure of the semiconductor to side angle radiation due to theshielding being spaced apart from the semiconductor.

[0023] A better method of shielding involves using an integrated shield,where the package itself is the shield. The best example of this isSpace Electronics Inc.'s RAD-PAK® technology, patent application Ser.No. 08/372,289 where the material in the package and the package designis optimized for the natural space radiation environment. However thismethod focuses on single-sided MCMs and monolithic ICS. These designsare acceptable for most applications but do not maximize the density ofintegrated circuit designs.

[0024] The inventions described herein will provide:

[0025] Improved shielding in all axial directions

[0026] Ability to take advantage of current generation IC technologicaladvances

[0027] Lower cost due to

[0028] The use of commercially available dies at market prices

[0029] Improved Delivery times

[0030] Higher density of integrated circuits

[0031] In addition, the inventions are improvements to patentapplication Ser. No. 08/372,289, titled Radiation Shielding ofIntegrated Circuits and Multi-Chip Modules in Ceramic and MetalPackages. These designs provide 3-dimensional techniques which result inlighter and more dense Multi-Chip modules (MCMs). Several new designapproaches are described, each with its attendant advantages andcost/performance characteristics.

Prior Art method of making Multi-Chip Modules

[0032] A typical prior art metal or ceramic packaged integrated circuitor multi-chip module assembly consists of silicon integrated circuit diemounted on a substrate (ceramic) which is then mounted to the metal basewith wirebonds connecting the substrate to the wire bond packagepads/posts. (FIG. 1) The base is sealed with a metal lid usingresistance welding or solder sealing techniques.

[0033] The final packaged devices are tested for conformance tomanufacturer's specifications and those that pass are delivered. Thesedevices would not work in the typical space application “as is” sincethe housing is very thin (approximately 3 to 8 mils/metal orapproximately 10 to 40 mils/ceramic) and is designed for mechanicalstructures only.

[0034] A ceramic or metal (usually Kovar) lid is utilized to seal thepackage. Typical packages do not use metal on the base except for heatsinking purposes and metallization of the ceramic for wire bond and dieattach purposes.

SUMMARY OF THE INVENTION

[0035] The process begins with use of commercially available softwarelike “Space Radiation Version 4.0” to model the application environmentbased on orbit or trajectory information. A dose versus depth curve isthe generated output. With the dose versus depth curve and knowing theradiation tolerance of the dice, the required amount of shielding to beused in the package can be calculated. By plotting the die tolerance onthe dose versus depth curve, and the inherent satellite shielding, therequired amount of shielding from the integrated circuit package can bedetermine to insure that the integrated circuit will survive over thesatellite mission life.

[0036] In the invention, the 3-dimensional radiation shielded MCM iscomprised of a double-sided substrate (either ceramic or printed circuitboard) with IC die mounted to both sides. Two configurations ofsubstrates exist, substrates mounted into packages and substrates whichare an integrated part of the package. In all configurations thepackages must be hermetically sealed if the part is to be used in spaceenvironments.

[0037] The first configuration involves attaching the substrate within abase package comprised of radiation shielding material. Electricalconnections are made from the substrate through insulating feed throughsthat are attached to package leads. A radiation shielding lid is sealedto the base to from a hermetic seal.

[0038] The second configuration integrates the substrates into thepackage. This configuration consists of; a double-sided substrate(ceramic or printed circuit board) with the IC die attached and wirebonded, a lid and side-wall combination comprised of radiation shieldingmaterial which is sealed to the substrate with a seal ring. Electricalconnections are made from the screened inter connects within thesubstrate which are then attached to the external package leads. (FIG.4)

[0039] To mechanically hold the substrates in the third configuration,the substrates is sealed inside a package comprised of side walls andlids comprised of radiation shielding material or sandwiched between theside-walls. The package is designed with two cavities, one for eachsubstrate or a single integrated top and bottom sided substrate. Thesubstrates are wire bonded tσ the package wire bond pads The wire bondpads connect to the external leads (FIG. 5).

[0040] In a fourth configuration, two substrates are mounted on a dualcavitied base (FIG. 11). The integrated circuits are mounted on thesubstrate with electrical connections made to package leads outside thepackage through insulating electrical feed throughs in the base. The twolids and the base are comprised of radiation shielding material.

[0041] In the third and fourth configuration, two lid types can beutilized per side: 1) A single shield which also is the lid and providesa hermetic seal (FIG. 6), or 2) two lids, an internal shield (lid) whichdoes not provide a hermetic seal, and an outer “standard” lid whichprovides the hermetic seal (FIG. 7). All lid types can be flat orprovide sidewall shielding. This version is used when extra radiationshielding is required and for sealing and mechanical reasons, anon-radiation shielding material needs to be used to make a hermeticseal

[0042] The preferred embodiment of the invention for the 3-dimensionalradiation shielded MCM concept will result in at least a ten foldimprovement in the devices' ability to meet a given total dose and isstructurally and thermally stable. In the preferred embodiment shieldingwould be composed of a high Z material or a mixture of high Z/Low Zmaterial. Where High Z is defined as material with an atomic numbergreater than 40.

[0043] Lead configurations can be of many types (pin-grid array, flatpackage, dual-in-line packages, can packages, etc.). The process anddesign steps to achieving a fully integrated, shielded device aredescribed in the Preferred Embodiment.

BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The above mentioned and other objects and features of thisinvention and the manner of attaining them will become apparent, and theinvention itself will be best understood by reference to the followingdescription of the embodiment of the invention in conjunction with theaccompanying drawings, wherein:

[0045]FIG. 1 is a top and side view of a typical prior art metal orceramic Multi-Chip module packaged integrated circuit assembly

[0046]FIG. 2 is a top and side view of a typical prior art integratedcircuit with the substrate as the base of the package.

[0047]FIG. 3 is a top and side view of a double sided single substrate.

[0048]FIG. 4 is a top and side view of a double sided three dimensionalmulti-chip module using a radiation shielding lid and side-wallcombination with the substrate integrated as part of the package.

[0049]FIG. 5 is a top and side view of Double sided three dimensionalmulti-chip module in a radiation shielded package with the substratesinside the package and attached to a base.

[0050]FIG. 6. is a top and side view of a double sided three dimensionalmulti-chip module with top and bottom radiation shielding lids, a topand bottom side-wall and a radiation shielding die attach slug.

[0051]FIG. 7. is a top and side view of a double sided radiationshielded three dimensional multi-chip module with two different sets oflids, one comprised of radiation shielding material and one standardpackaging material, and with a substrate internal to the package.

[0052]FIG. 7A. is a top and side view of a three dimensional multi-chipmodule with side shielded die attach slugs and one set of high-zmaterial lids.

[0053]FIG. 8. is a top and side view of a radiation shielded doublesided three dimensional multi-chip module with 2 different lids,shielded die attach slugs, and the substrate integrated into thepackage.

[0054]FIG. 9 is a top and side view of a radiation shielded double sidedthree dimensional multichip module with an internal shielding ringattached to the top and bottom surface of the substrate.

[0055]FIG. 10 is a top and side view of a radiation shielded doublesided three dimensional multi-chip module with one set of high-zmaterial lids and with the substrate integrated into the package.

[0056]FIG. 11 Is a side view of a radiation shielded double sided threedimensional multi-chip module with a dual cavity base composed ofshielding material, two substrate attached to the well of both cavitiesand two shielding lids.

DETAILED DESCRIPTION OF THE INVENTION

[0057]FIGS. 1 and 2 show typical prior art multi-chip modules. MultipleIntegrated Circuit (IC) dice 1 are attached to a substrate 4. Thesubstrate is then attached to the base of the package 2. A lid 10 isthen attached to the base of the package. Electrical connections aremade using die wire bonds 7 which are attached electrically to thepreprinted circuit on the substrate. The substrate is attachedelectrically via wire bonds 6 from the substrate 4 to package leads 5that pass through the package through insulating feed throughs 3.

[0058]FIG. 3 shows a double sided multi-chip module without the package.In this configuration the integrated circuits 1 are mounted on bothsides of the substrate 4. Package leads 5 are attached on both sides ofsubstrate 4.

[0059] This invention involves a multi-step process that includesradiation evaluation, and flexibility in the design of the package. Thesteps are as follows:

[0060] 1. Using standard space radiation models such as NASA's AP8 orAE8, the fluence, energy and the species of radiation present in aspecific orbit or application is calculated. For orbits around theearth, this calculation includes trapped electrons, trapped protons,solar flares, and cosmic rays. From this table of radiation as afunction of fluence, species and energy, a radiation transport code likeSpace Radiation version 4.0 is used to generate a total dose versusdepth curve for the application. The transport calculation is based uponshielding material density, shielding material thickness, type ofmaterial used to stop radiation (silicon), radiation energy level versusdosage (for the orbit/mission), and package design. Calculations arecompleted through all shielding elements (base, lids, sidewalls, etc.)

[0061] 2. The total dose tolerance of all integrated circuits or othercircuit elements is determined. This is completed by radiationcharacterization/testing of each individual device type.

[0062] 3. Using the dose versus depth curve and the die total doseradiation failure level the amount of shielding required is calculated.The type of MCM package used is then designed based on the size,function and type of the integrated that will go into the package, andthe amount of radiation shielding required. The required shieldingthickness is the minimum amount to bring the total dose radiation levelbelow the total dose die failure level of all die within the multi-chipmodule.

[0063] 4. Each package is constructed using a combination of parts: acombination of lids and side-walls or lid and side-wall combinations,one or two substrates, package leads, multiple die with optional dieattach slugs.

[0064] a. In a configuration using a base, the base is manufacturedusing a high-Z material or high-Z/low-Z combination such ascopper-tungsten alloy or tantalum, or similar shielding material inthickness sufficient to shield the total dose tolerance to a value lessthan the integrated circuit die tolerance as calculated in paragraph 3above.

[0065] b. The substrates are manufactured using high temperatureco-fired ceramic (A1 ₂O₃) with screened inter connects or printedcircuit boards mounted on a ceramic substrate to provide interconnectionbetween the circuit elements and a location for mechanical mounting ofcircuit elements.

[0066] c. The lids or lid and side-wall combinations are manufacturedusing a high-Z material such as tantalum, or a high-Z/low-Z materialsuch as copper-tungsten alloy, or similar shielding material inthickness sufficient to shield the total dose tolerance to a value lessthan the integrated circuit die tolerance as calculated in paragraph 3above. All packages must have hermetic seals to prevent moisture andpossible corrosives from entering the package.

[0067] d. The side wall is manufactured using either a high-Z orhigh-Z/low-Z combination material or a standard packaging material likeceramic, PCB, kovar or other metal. When side shielding is required anda high Z or high Z/low Z material is used, a thickness sufficient toshield the total dose tolerance to a value less than the IC dietolerance as calculated in paragraph 3 above. These calculations arecompleted in conjunction with the calculations for the base and lids asdescribed in paragraphs 4.a and 4.c. If base and lid shielding providessufficient reduction in total dose levels, the sidewalls can bemanufactured using non-shielding material (Kovar or ceramic).

[0068] e. The package leads are attached to the base or substrate usingnormal lead attach techniques (brazing, soldering etc.) and can beshaped into any normal lead configuration (dual-in-line, flat leads, pingrid arrays, etc.)

[0069] f. The optional die attach slugs or shielding ring aremanufactured using a high-Z material such as copper-tungsten alloy ortantalum or similar shielding material in thickness sufficient to shieldthe total dose tolerance to a value less than the integrated circuit dietolerance as calculated in paragraph 3 above. The slugs are used toshield individual IC die.

[0070] 5. The preferred approach is to use a single substrate, and usethe lid and side-wall combination.

[0071] a) The substrate is manufactured from either high temperatureco-fired ceramic with a screened interconnect or a printed circuit boardmaterial mounted on ceramic.

[0072] b) The lid and side-wall combinations are manufactured using highZ/Low Z or high-Z material such as copper-tungsten alloy or tantalum, orsimilar shielding material in thickness sufficient to shield the totaldose tolerance to a value less than the integrated circuit die toleranceas calculated in paragraph 3 above.

[0073] c) The package leads are attached to the substrate using normallead attach techniques (brazing, soldering, etc.) and can be shaped intoany normal lead configuration (dual-in-line, flat leads, pin gridarrays, etc.)

[0074] 6. FIG. 4 represents the preferred method for optimal shielding.The Dice 1 are attached mechanically by standard space qualified methodor those set forth in step 8, to a high temperature co-fired ceramicsubstrate 4. The shield 20 is a lid and side-wall combination givingalmost 360 degree protection to the package. The shielding lid andside-wall combination 20 is attached to the substrate 4 by a seal ring103 which preferably is comprised of Gold or a similar metal to insure ahermetic seal. The dice 1 are electrically connected by wire bonds 7 tothe substrate which contains screened inter connects. The inter-connectspass through the substrate and attach to the package leads 5.

[0075] 7 FIG. 5 shows an example of a package with a base 22, shieldinglid 120 and the substrate 4 attached inside of the package. In this caseinsulating feed throughs 3 are used for the package leads 5 to passthrough the package.

[0076] 8. The circuit elements (integrated circuits plus all otherelements such as transistors, diodes, capacitors, resistors, inductors,etc.) are generally mounted to the substrates using standard MCMtechniques (soldering, epoxy, eutectic, silver glass, etc.). Allelements requiring wire bonding are wire bonded. The substrates aremounted into the base using standard MCM substrate mounting techniques(epoxy soldering, eutectic, silver glass, etc.). The lids are sealed tothe side-wall 42 using solder, glass or epoxy. The substrate can becomprised of ceramic, PCB or similar material.

[0077] 9. Another option is shown in FIG. 6. Two lids comprised ofradiation shielding material 120 are sealed to the side-wall 40, usingsolder (for sealing to metal, metallized or ceramic), epoxy (for sealingto metal, metallized or ceramic), resistance welding (for sealing tometal, or metallized), eutectic (for sealing to Au—Sn, Au—Si orequivalent, metals or metallized), or brazing (for Ag—Cu) techniques.The Dice 1, are optionally attached to radiation shielding die attachslugs 30. The substrate 4 is attached to the side-wall 40 by a seal ring103. The package leads 5 are attached to the substrate inter connects.

[0078] 10. FIG. 7 shows another option that allows for thicker radiationshielding of the lid while maintaining a hermetic seal. FIG. 7 differsfrom FIG. 6 in that there are two sets of if lids. There is an innerradiation shielding lid 120 and an outer sealing lid 26 that can becomposed of a standard package material. Because many of the standardradiation shielding materials make poor seals with standard packagingmaterial the outer sealing lid 27 is required. The set of lids isattached to the side-walls. In the configuration shown in FIG. 7 thesubstrate 4 sandwiched between the side-wall 40.

[0079] 11. In FIG. 7A, an optional technique for die attach slugs 32 isto provide side angle shielding by manufacturing the shielding slugs 32with side walls in a well configuration to reduce radiation from thenormally unshielded side angles and provide 360 degree shielding. Thewire bond wires are looped over the side walls of the die attach slug toprovide access. This technique is applicable to ceramic as well as metalpackages. For some wire thickness' and operating conditions insulatedwire is used to connect the wire bonds 7 over the side wall. In thisfigure, there is a single shielding lid 120 on the top and bottom of thepackage.

[0080] 12. FIG. 8 is similar to FIG. 7 except that there are die attachslugs 30 made of radiation shielding material to shield the integratedcircuits (or dice) from side angle radiation.

[0081] 13. FIG. 9 shows a multi-chip module similar to FIG. 6, here ashielding ring 50 that is attached to the top and bottom side of thesubstrate 4 and runs around the entire edge of the substrate shieldingthe dice from side angle radiation.

[0082] 14. FIG. 10 shows a top and bottom radiation shielding lid 120.The substrate 4 is integrated into the package via attachment to theside-wall 40. The side-wall 40 can be comprised of ceramic, PCB ormetal. The radiation shielding lid 120 is sealed to the side-wall 40 bya seal ring 103.

[0083] 15. FIG. 11 shows a dual cavity base 22 composed of radiationshielding material.

[0084] Two substrates 4 are attached to the base 22, one on the top andone on the bottom cavity of the base 22. The dice are attached to thesubstrates 4 electrical connections are by wire bonds 7 from the die tothe substrate, which then connects to package leads 5 which pass throughthe base 22 through insulating feed throughs 3.

[0085] 16. In all configurations, for sealing, an optional hole can bydrilled into the lids to create a vent for vacuum removal of moistureand/or as a gaseous purge of the internal cavity during the sealingprocess. The hole is then sealed up in either a vacuum or an environmentwith a nonreacting gas such as nitrogen.

What is claimed is:
 1. A radiation shielded multi-chip module, comprising: (a) a base constructed from a radiation shielding material with a plurality of non-conducting feed throughs; and (b) a substrate with a plurality of integrated circuit devices attached to a top side of said substrate and a plurality of integrated circuit devices attached to a bottom side of said substrate, wherein said substrate is attached to the inside of said base; and (c) a lid constructed from a radiation shielding material, wherein said base is secured to an inner surface of said base member; and (d) a plurality of package leads passing through said plurality of non-conducting feed throughs in said base and electrically attached to said plurality of integrated circuit devices.
 2. A radiation shielded multi-chip module according to claim 1, wherein said radiation shielding material is comprised of a high Z/low Z alloy.
 3. A radiation shielded multi-chip module according to claim 1, wherein said radiation shielding material is comprised of a high Z material.
 4. A radiation shielded integrated circuit device according to claim 1, wherein said radiation shielding material is comprised of a Copper Tungsten alloy.
 5. A radiation shielded multi-chip module according to claim 1, wherein said radiation shielding material is comprised of Tungsten.
 6. A radiation shielded multi-chip module according to claim 1, wherein a plurality of die attach slugs composed of radiation shielding material are disposed between and attached to said substrate and said plurality of integrated circuit die.
 7. A radiation shielded multi-chip module as recited in claim 1, wherein a thickness of said base and said lid is determined by, a calculation of the radiation for a specific task; and a total radiation dose tolerance of all integrated circuits attached to said base; and a radiation transport calculation, wherein the thickness of said shielding material is calculated as a function of said radiation for a specific task, said total radiation dose tolerance, and the density and thickness of said shielding material and is derived from said radiation transport calculation.
 8. A radiation shielded multi-chip module, comprising: (a) a top lid and side-wall combination composed of a radiation shielding material; and (b) a bottom lid and side-wall combination composed of a radiation shielding material; and (c) a substrate with a plurality of integrated circuit devices attached to a top side of said substrate and a plurality of integrated circuit devices attached to a bottom side of said substrate, wherein said substrate is attached to said top and said bottom lid and side-wall combination by a seal ring on said substrates top and bottom surface; and (d) a plurality of package leads attached electrically to said plurality of integrated circuit devices and mechanically attached to said substrate.
 9. A radiation shielded multi-chip module as recited in claim 8, wherein the thickness of said base and said lid is determined by, (a) a calculation of the radiation for a specific task; and (b) a total radiation dose tolerance of all integrated circuits attached to said base; and (c) a radiation transport calculation, wherein the thickness of said shielding material is calculated as a function of said radiation for a specific task, said total radiation dose tolerance, and the density and thickness of said shielding material and is derived from said radiation transport calculation.
 10. A radiation shielded multi-chip module as recited in claim 8, wherein said radiation shielding material is comprised Tungsten.
 11. A radiation shielded multi-chip module as recited in claim 8, wherein said radiation shielding material is comprised of a high Z/low Z material.
 12. A radiation shielded multi-chip module as recited in claim 8, wherein said radiation shielding material is comprised of a Copper Tungsten alloy.
 13. A radiation shielded multi-chip module as recited in claim 8, wherein said radiation shielding material is comprised of a high Z material.
 14. A radiation shielded multi-chip module as recited in claim 8, wherein said seal ring makes a hermetic seal between said top and said bottom lid and side-wall combination and said substrate.
 15. A radiation shielded multi-chip module as recited in claim 8, wherein said top lid and side-wall combination or said bottom lid and side-wall combination has a small hole to allow for venting during sealing, and said small hole is subsequently sealed to maintain a hermetic seal.
 16. A radiation shielded multi-chip module as recited in claim 8, wherein said plurality of integrated circuit devices are electrically attached by a plurality of screened interconnects within said substrate, said screened interconnects are electrically attached to said plurality of package leads.
 17. A radiation shielded multi-chip module, comprising: (a) A top side-wall; and (b) A bottom side-wall; and (c) A substrate comprised of a plurality of integrated circuit devices attached to a top side of said substrate and a plurality of integrated circuit devices attached to a bottom side of said substrate, wherein said top side of said substrate is attached to the bottom side of said top side-wall, and said bottom side of said substrate is attached to the top surface of said bottom side-wall; and (d) A top lid constructed from a radiation shielding material, wherein said top lid is hermetically sealed to the top surface of said top side-wall; and (e) A bottom lid constructed from a radiation shielding material, wherein said bottom lid is hermetically sealed to the bottom surface of said bottom side-wall; and (f) A plurality of package leads attached electrically to said plurality of integrated circuit devices.
 18. A radiation shielded multi-chip module as recited in claim 17, wherein said top lid and said bottom lid are composed of a high Z/low Z alloy.
 19. A radiation shielded multi-chip module as recited in claim 17, wherein said top lid and said bottom lid are composed of a high Z material.
 20. A radiation shielded multi-chip module as recited in claim 17, wherein said top lid and said bottom lid are composed of a Copper Tungsten alloy.
 21. A radiation shielded multi-chip module as recited in claim 17, wherein said top lid and said bottom lid are composed of a Tungsten.
 22. A radiation shielded multi-chip module as recited in claim 17, wherein (a) said top lid is comprised of (1) a first top lid which is composed of a packaging material and (2) an inner top lid composed of a radiation shielding material attached to said first top lid, wherein said first top lid makes a seal with said top surface of said side wall; and (b) said bottom lid is comprised of (1) a first bottom lid which is composed of a packaging material and (2) an inner bottom lid composed of a radiation shielding material and attached to said first bottom lid, wherein said first bottom lid makes a seal with said bottom surface of said side wall.
 23. A radiation shielded multi-chip module as recited in claim 22, wherein said radiation shielding material is comprised of a high Z/low Z material.
 24. A radiation shielded multi-chip module as recited in claim 22, wherein said radiation shielding material is comprised of a Copper Tungsten alloy.
 25. A radiation shielded multi-chip module according to claim 17, further including, a plurality of die attach slugs composed of radiation shielding material that are disposed between and attached to said substrate and said plurality of integrated circuit die.
 26. A radiation shielded multi-chip module as recited in claim 17, wherein a shielding ring composed of a radiation shielding material is attached to said top and said bottom surface of said substrate.
 27. A radiation shielded multi-chip module, comprising: (a) a dual cavity base with a top well and a bottom well and with a plurality of non-conducting feed throughs; and (b) a top substrate with a plurality of integrated circuit devices attached to a top side of said top substrate, wherein said top substrate is attached to the inside surface of said top well on said dual cavity base; and (c) a bottom substrate with a plurality of integrated circuit devices attached to a bottom side of said bottom substrate wherein said bottom substrate is attached to the inside surface of said bottom cavity of said dual cavity base; and (d) a top lid comprised of radiation shielding material which is attached to said top well of said dual cavity base forming a sealed cavity; and (e) a bottom lid comprised of radiation shielding material which is attached to said bottom well of said dual cavity base forming a sealed cavity; and (f) a plurality of package leads passing through said plurality of non-conducting feed throughs in said dual cavity base and electrically attached to said plurality of integrated circuit devices.
 28. A radiation shielded multi-chip module as recited in claim 27, wherein said radiation shielding material is comprised of a high Z/low Z material.
 29. A radiation shielded multi-chip module as recited in claim 27, wherein said radiation shielding material is comprised of a Copper Tungsten alloy.
 30. A radiation shielded multi-chip module as recited in claim 27, wherein said radiation shielding material is comprised of Tungsten.
 31. A radiation shielded multi-chip module as recited in claim 27, wherein said radiation shielding material is comprised of a high Z material.
 32. A radiation shielded multi-chip module as recited in claim 27, wherein (a) said top lid is comprised of (1) a first top lid which is composed of a packaging material and (2) an inner top lid composed of a radiation shielding material attached to said first top lid, wherein said first top lid makes a seal with a top surface of said dual cavity base; and (b) said bottom lid is comprised of (1) a first bottom lid which is composed of a packaging material and (2) an inner bottom lid composed of a radiation shielding material attached to said first bottom lid, wherein said first bottom lid makes a seal with a bottom surface of said dual cavity base. 